Narcan (naloxone) is a nasal spray that reverses opioid overdoses by knocking opioids off receptors in the brain. It works in minutes, requires no medical training, and cannot harm someone who hasn’t taken opioids. The nasal spray is available over the counter at most pharmacies, and giving it correctly comes down to a handful of simple steps.
Recognizing an Overdose
Before reaching for Narcan, you need to know what an opioid overdose looks like. Three signs appear together so reliably that medical professionals call them the “opioid overdose triad”: pinpoint pupils, slowed or stopped breathing, and reduced consciousness. A person overdosing may breathe as few as 4 to 6 times per minute (normal is 12 to 20), or their breathing may stop entirely. Their lips or fingertips may turn blue or grayish, a sign the body isn’t getting enough oxygen.
The person may be completely unresponsive to shouting or a firm rub on the breastbone. If you see someone with tiny pupils, barely breathing or not breathing at all, and you can’t wake them up, treat it as an overdose. Acting quickly matters more than being 100% certain.
How to Give the Nasal Spray
The standard Narcan nasal spray delivers 4 mg of naloxone in a single, pre-loaded dose. There’s no priming, no measuring, and no assembly. Each device works once. Here’s the full process, based on the FDA-approved instructions:
- Call 911 first. Narcan buys time, but it doesn’t replace emergency medical care.
- Lay the person on their back. Tilt their head back slightly and support the neck with your hand.
- Open the package. Peel back the tab to remove the device. Do not test or prime it.
- Hold the device correctly. Place your thumb on the bottom of the plunger and your index and middle fingers on either side of the nozzle.
- Insert the nozzle. Gently slide the tip into one nostril until your two fingers rest against the base of the person’s nose.
- Press the plunger firmly. One solid press delivers the full dose. Remove the device from the nostril.
- Place the person in the recovery position. Roll them onto their side with the top knee bent forward for stability. This keeps their airway open and prevents choking if they vomit.
If the person doesn’t start breathing normally or wake up within 2 to 3 minutes, give a second dose in the other nostril using a new device. You can continue giving additional doses every 2 to 3 minutes, alternating nostrils each time, until help arrives or the person responds.
If You Have an Injectable Kit
Some naloxone kits contain a vial and syringe instead of a nasal spray. The preferred injection site is the outer middle thigh (the large muscle on the front-outside of the leg). An alternate site is the upper outer arm. Clean the skin with an alcohol swab if one is available, but don’t delay treatment to find one. You can inject through clothing if necessary.
Insert the needle straight in at a 90-degree angle, push the plunger down completely, then pull the needle out the same way it went in. Don’t recap the needle. The thigh is preferred because the larger muscle absorbs the medication faster than the arm.
How Quickly It Works
Naloxone crosses into the brain rapidly and starts displacing opioids from receptors within minutes. It needs to block roughly half of the brain’s opioid receptors to reverse an overdose. For nasal and injectable forms, most people see a response within 2 to 5 minutes. That’s why the instructions say to wait 2 to 3 minutes before considering a second dose.
The critical limitation is duration. Naloxone’s half-life in adults ranges from 30 to 80 minutes, which means it wears off well before many opioids do. Fentanyl, methadone, and other long-acting opioids can outlast naloxone by hours. This is exactly why calling 911 is non-negotiable. A person who wakes up after Narcan can slip back into an overdose once the naloxone clears their system. Medical guidelines recommend monitoring for 6 to 12 hours after naloxone is given.
What Happens When the Person Wakes Up
Naloxone doesn’t just reverse the overdose. It strips opioids off brain receptors almost instantly, which can throw a person with opioid dependence into rapid withdrawal. About half of people in this situation hit peak withdrawal symptoms within 15 minutes, and roughly 75% peak within 30 minutes.
Expect the person to feel terrible. Common symptoms include nausea, vomiting, stomach cramps, muscle aches, sweating, shaking, restlessness, and anxiety. Their eyes may water, nose may run, and they may have goosebumps and hot or cold flashes. These symptoms are deeply unpleasant but not life-threatening.
The person may be confused, agitated, or even angry. They may want to leave or use again. Stay calm, explain what happened, and try to keep them in place until paramedics arrive. If they do leave, let them know the Narcan will wear off and the overdose can return.
When One Dose Isn’t Enough
Standard Narcan delivers 4 mg per spray. For most opioid overdoses, one or two doses are sufficient. Overdoses involving extremely potent synthetic opioids like carfentanil (roughly 100 times stronger than fentanyl) may require three or more doses. A higher-dose nasal spray called Kloxxado delivers 8 mg, but harm reduction experts generally recommend carrying multiple standard 4 mg doses rather than relying on a single high-dose product. The reasoning: multiple standard doses give you more control, cost less, and reduce the severity of precipitated withdrawal.
Storing Narcan So It’s Ready When Needed
Keep Narcan between 59°F and 86°F (15°C to 30°C) and out of direct sunlight. That said, the medication is remarkably stable. Studies show naloxone remains effective after being frozen, thawed, and even exposed to high heat. One study found that injectable naloxone expired for 30 years still contained more than 90% of its active ingredient. If your Narcan has been sitting in a car glovebox or a backpack through temperature swings, it’s almost certainly still usable. An expired dose is always better than no dose.
Most packages carry a two-year expiration date. Check yours periodically and replace it when it expires, but don’t throw away expired Narcan unless you have a fresh supply to replace it.
Legal Protections for Bystanders
Every U.S. state has some form of Good Samaritan law that provides legal protection to people who call 911 or assist during an overdose. The specifics vary. Some states protect bystanders from arrest, others only from prosecution or charge, and a few only offer reduced sentencing. These protections typically cover low-level drug offenses like possession of drugs or paraphernalia. The strongest protections, those shielding from arrest rather than just prosecution, appear to be most effective at encouraging people to call for help without fear.
Narcan itself is legal to carry and administer in all 50 states without a prescription. You cannot get in trouble for giving it to someone, and it causes no harm if given to a person who isn’t experiencing an opioid overdose.